I had Walker turbos on my camaro back in high school. It had a really odd resonance or drone at part throttle. It may have been a placement issue Your Mileage May Vary as they say.
Do you have tail pipes that go over the axle? Do you have a balance pipe?
My dad has cherrybombs on his 55 and he loves em. I hated em until all the packing fell apart. Walker and Heartthrob both make good quality turbo mufflers